Oil tank isolating valve

Abstract

The utility model provides an isolating valve of an oil tank. The isolating valve comprises a valve body, a positive pressure valve unit, a negative pressure valve unit and an electromagnetic valve unit, a first cavity, a second cavity and a partition plate are arranged in the valve body, and the second cavity is arranged above the first cavity; the positive pressure valve unit comprises a positive pressure valve seat, a positive pressure spring and a sealing gasket, and the positive pressure valve seat is located in the first cavity; the upper surface of the sealing gasket is provided with a first lip used for being attached to the partition plate in a sealed mode and a second lip used for being attached to the negative pressure valve unit in a sealed mode. The lower surface of the sealing gasket is connected with the top face of the positive pressure valve seat. The negative pressure valve unit is used for abutting against the second lip, and a gap is formed between the negative pressure valve unit and the communicating hole; the electromagnetic valve unit is installed in the second cavity. By means of the design, the distance between the positive pressure valve seat and the negative pressure valve unit can be shortened, more space is saved, meanwhile, the negative pressure valve unit with small pressure is arranged at one end of the electromagnetic valve unit, suction force needed by the electromagnetic valve unit is smaller, the size of the electromagnetic valve unit can be reduced, and the size of the oil tank isolating valve is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of valves, in particular to a fuel tank isolation valve. Background Art

[0002] In a gasoline vapor emission system, gasoline vapor generated in a fuel tank is discharged to a carbon canister through an exhaust valve and effectively adsorbed by activated carbon therein. After the engine is started, fresh air is inhaled into the carbon canister, and the fuel vapor adsorbed by the activated carbon in the carbon canister is brought back into the engine for combustion to improve fuel efficiency. However, in a plug-in hybrid vehicle model, there is a long-term electric drive mode. In this mode, the carbon canister has no desorption function, which easily leads to the adsorption capacity of the carbon canister reaching saturation. After that, the fuel vapor will be directly discharged into the atmosphere, resulting in environmental pollution and fuel waste. In addition, when the vehicle is in the electric drive mode for a long time, the fuel continuously volatilizes and accumulates, resulting in too high pressure in the fuel tank, thus damaging the fuel tank. At this time, the valve needs to have an automatic pressure relief function. Or the fuel in the fuel tank is used up quickly, resulting in too small air pressure in the fuel tank, thus being damaged by the extrusion of the external atmospheric pressure. At this time, it is required that the valve has an automatic pressure boosting function.

[0003] In the prior art, the invention patent with the publication number of CN103328805A discloses an isolation valve for rapid decompression of a high-pressure fuel tank. However, the structure of the isolation valve is relatively complex and the volume is relatively large, making the manufacturing inconvenient and not convenient for the overall vehicle layout. Utility Model Content

[0004] In view of this, the utility model provides a fuel tank isolation valve to solve the technical problems that the isolation valve in the above background art has a relatively complex structure and a relatively large volume, making the manufacturing inconvenient and not convenient for the overall vehicle layout.

[0005] The technical solution of the utility model is realized as follows:

[0006] The utility model provides a fuel tank isolation valve, which includes a valve body, a positive pressure valve unit, a negative pressure valve unit and a solenoid valve unit, wherein:

[0007] A first cavity, a second cavity and a partition are arranged in the valve body. The second cavity is arranged above the first cavity. The first cavity and the second cavity are respectively connected with a first channel for connecting the carbon canister and a second channel for connecting the fuel tank. The partition is arranged between the first cavity and the second cavity, and a communication hole is arranged on the partition;

[0008] The positive pressure valve unit includes a positive pressure valve seat, a positive pressure spring, and a gasket. The positive pressure valve seat is located in the first cavity. One end of the positive pressure spring abuts against the bottom of the first cavity, and the other end of the positive pressure spring abuts against the positive pressure valve seat. The upper surface of the gasket is provided with a first lip and a second lip. The first lip is used for sealingly fitting with the partition plate, and the second lip is used for sealingly fitting with the negative pressure valve unit. The lower surface of the gasket is connected to the top surface of the positive pressure valve seat.

[0009] The negative pressure valve unit is used to abut against the second lip, and there is a gap between the negative pressure valve unit and the peripheral wall of the communication hole.

[0010] The solenoid valve unit is installed in the second cavity and is connected to the negative pressure valve unit.

[0011] Wherein:

[0012] After the medium enters the second cavity from the second channel, it enters the first cavity through the gap and is discharged to the carbon canister through the first channel; or, after the medium enters the first cavity from the first channel, it enters the second cavity through the gap and is replenished to the fuel tank through the first channel.

[0013] On the basis of the above technical solutions, preferably, a second guide plate is provided at the bottom of the positive pressure valve seat, and a first guide plate is provided at the bottom of the first cavity. The inner diameter of the first guide plate is larger than the inner diameter of the second guide plate, and the positive pressure spring is located between the second guide plate and the first guide plate.

[0014] On the basis of the above technical solutions, preferably, a plurality of air vent holes are provided on the outer wall of the second guide plate, and the first guide plate includes at least two arc-shaped plates arranged at intervals.

[0015] On the basis of the above technical solutions, preferably, a flow limiting valve is further included. A flow limiting hole communicating with the first channel is provided at the bottom of the first cavity, and the flow limiting valve is installed in the flow limiting hole. The flow limiting valve is provided with an air guide hole communicating the first cavity and the first channel.

[0016] On the basis of the above technical solutions, preferably, a limiting protrusion is provided at the top of the flow limiting hole, and a guide post coaxial with the flow limiting hole is provided in the first channel.

[0017] The fuel tank isolation valve further includes a flow limiting spring. The flow limiting spring is sleeved on the guide post. One end of the flow limiting spring abuts against the inner wall of the second channel, and the other end abuts against the bottom surface of the flow limiting valve, so that the top surface of the flow limiting valve abuts against the limiting protrusion.

[0018] Based on the above technical solutions, preferably, the negative pressure valve unit includes a negative pressure valve seat and a negative pressure spring. One end of the negative pressure spring abuts against the solenoid valve unit, and the other end of the negative pressure spring abuts against the negative pressure valve seat to make the negative pressure valve seat abut against the second lip; a gap is provided between the negative pressure valve seat and the peripheral wall of the communication hole.

[0019] Based on the above technical solutions, preferably, the solenoid valve unit includes a housing, a coil, and a guide rod; the housing is connected to the valve body, and a sliding hole is provided inside the housing; the coil is arranged on the top of the housing and is used to magnetically attract the guide rod after being energized; the guide rod is made of a magnetizable material and is slidably installed in the sliding hole.

[0020] Based on the above technical solutions, preferably, the solenoid valve unit further includes a limit seat located in the second cavity. The limit seat includes a baffle and a guide cylinder; the baffle is connected to the guide rod, and the baffle can abut against the end of the sliding hole; the guide cylinder is connected to one end of the baffle away from the coil, and the negative pressure spring is sleeved on the guide rod and is located inside the guide cylinder.

[0021] Based on the above technical solutions, preferably, the negative pressure valve seat includes a base and a connecting cylinder. The base is used to abut against the second lip; the connecting cylinder is arranged on the top of the base, a connecting cavity is provided inside the connecting cylinder, a mounting hole is provided on the top surface of the connecting cylinder, the diameter of the mounting hole is smaller than the diameter of the inner wall of the connecting cavity, and an axial groove section is provided at one end of the guide rod away from the coil. The axial groove section is arranged in the mounting hole, and the end of the guide rod is located inside the connecting cavity.

[0022] Based on the above technical solutions, preferably, a mounting groove is provided on the outer wall of the connecting cylinder. The mounting groove communicates the connecting cavity and the mounting hole, and the width of the mounting groove is larger than the bottom diameter of the axial groove section.

[0023] Based on the above technical solutions, preferably, a plurality of first rib plates are further provided inside the valve body. The plurality of first rib plates are circumferentially arranged along the inner wall of the second cavity. The first rib plates extend from the inner wall of the second cavity in the diameter direction of the second cavity, and one end of the first rib plate away from the inner wall of the second cavity is used to guide the negative pressure valve seat.

[0024] Based on the above technical solutions, preferably, a plurality of second rib plates are further provided inside the valve body. The plurality of second rib plates are circumferentially arranged along the inner wall of the first cavity, and the second rib plates are respectively connected to the inner wall of the first cavity and the partition plate.

[0025] The fuel tank cut-off valve of the present utility model has the following beneficial effects compared with the prior art:

[0026] (1) During the positive pressure relief operation, the medium enters the second cavity from the second channel. The pressure of the medium pushes the gasket and the positive pressure valve seat downward, so that the first lip disengages from the partition plate. The medium enters the first cavity from the gap and is discharged to the carbon canister through the second channel. During the negative pressure air supplement operation, the medium enters the first cavity from the first channel. The medium pushes the negative pressure valve unit upward, so that the second lip disengages from the negative pressure valve unit. The positive pressure valve seat makes the first lip keep abutting against the partition plate under the elastic force of the positive pressure spring. The medium enters the first cavity from the gap and is supplemented into the fuel tank through the first channel.

[0027] The above design can shorten the distance between the positive pressure valve seat and the negative pressure valve unit, thus saving more space. At the same time, the negative pressure valve unit with smaller pressure is arranged at one end of the solenoid valve unit, making the suction force required by the solenoid valve unit smaller. The solenoid valve unit can be made smaller accordingly, reducing the volume of the fuel tank isolation valve.

[0028] (2) By providing a second guide plate at the bottom of the positive pressure valve seat and a first guide plate at the bottom of the first cavity, the inner diameter of the first guide plate is larger than that of the second guide plate. The positive pressure spring is located between the second guide plate and the first guide plate, so that the elastic force direction of the positive pressure spring remains along the axis of the positive pressure valve seat, making the first lip of the gasket fit more tightly with the partition plate and improving the sealing effect.

[0029] (3) By providing a plurality of ventilation holes on the outer wall of the second guide plate, the first guide plate includes at least two arc plates arranged at intervals, increasing the ventilation area between the second guide plate and the first guide plate, avoiding affecting the flow of the gas medium, improving the efficiency of the medium flow, and thus improving the efficiency of pressure relief or air supplement.

[0030] (4) By connecting the baffle plate to the guide rod, the baffle plate can abut against the end of the sliding hole. The guide cylinder is connected to the end of the baffle plate away from the coil. The negative pressure spring is sleeved on the guide rod and is located inside the guide cylinder. One end of the negative pressure spring abuts against the baffle plate, and the other end of the negative pressure spring abuts against the negative pressure valve seat. The baffle plate abuts against the end of the sliding hole, forming a support point for the negative pressure spring, and the elastic force of the negative pressure spring will not decrease as the guide rod rises. When the negative pressure is eliminated, the negative pressure spring can drive the negative pressure valve seat to descend and reset, improving the stability and reliability of the device.

[0031] (5) An installation groove is provided on the outer wall of the connecting cylinder. The installation groove communicates with the connecting cavity and the installation hole. The width of the installation groove is greater than the bottom diameter of the shaft groove section. When installing the guide rod, the shaft groove section area of the guide rod is passed through the installation groove, and then the end of the guide rod can be placed in the connecting cavity, which improves the convenience of device installation and enhances the reliability and stability of the device.

[0032] (6) A plurality of first rib plates are further provided in the valve body. The plurality of first rib plates are arranged circumferentially along the inner wall of the second cavity. The first rib plates extend in the diameter direction of the second cavity from the inner wall of the second cavity. One end of the first rib plate away from the inner wall of the second cavity is used to guide the negative pressure valve seat. While the first rib plate can guide the negative pressure valve seat, it can also strengthen the strength of the partition plate, prevent the partition plate from being damaged due to excessive stress, and improve the reliability and stability of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0034] Figure 1 It is a cross-sectional view of the fuel tank cut-off valve of the present invention;

[0035] Figure 2 It is a three-dimensional view of the fuel tank cut-off valve of the present invention;

[0036] Figure 3 It is a cross-sectional view of the valve body of the present invention;

[0037] Figure 4 It is a three-dimensional view of the first cavity of the present invention;

[0038] Figure 5 It is a three-dimensional view of the second cavity of the present invention;

[0039] Figure 6 It is a three-dimensional view of the positive pressure valve unit of the present invention;

[0040] Figure 7 It is a cross-sectional view of the positive pressure valve unit of the present invention;

[0041] Figure 8 It is a three-dimensional view of the negative pressure valve seat of the present invention;

[0042] Figure 9 It is a structural schematic diagram of the connection between the negative pressure valve seat and the solenoid valve unit of the present invention;

[0043] Figure 10 This is a cross-sectional view of the solenoid valve unit of the present utility model;

[0044] Figure 11 This is a schematic diagram of the principle of the fuel tank isolation valve of the present utility model during positive pressure relief operation;

[0045] Figure 12 This is a schematic diagram of the principle of the fuel tank isolation valve of the present utility model during negative pressure air replenishment operation.

[0046] Explanation of reference numerals: 1 - valve body, 2 - positive pressure valve unit, 3 - negative pressure valve unit, 4 - solenoid valve unit, 5 - flow limiting valve, 6 - flow limiting spring;

[0047] 100 - gap;

[0048] 11 - first cavity, 111 - first guide plate, 1111 - arc plate, 112 - flow limiting hole, 1121 - limit protrusion, 12 - second cavity, 13 - partition plate, 131 - communication hole, 14 - first channel, 141 - guide post, 15 - second channel, 16 - first rib plate, 17 - second rib plate;

[0049] 21 - positive pressure valve seat, 211 - second guide plate, 2111 - ventilation hole, 22 - positive pressure spring, 23 - sealing gasket, 231 - first lip, 232 - second lip;

[0050] 31 - negative pressure valve seat, 311 - base, 312 - connecting cylinder, 3121 - connecting cavity, 3122 - mounting hole, 3123 - mounting groove, 32 - negative pressure spring;

[0051] 41 - housing, 411 - sliding hole, 42 - coil, 43 - guide rod, 431 - shaft groove section, 44 - limit seat, 441 - baffle plate, 442 - guide cylinder;

[0052] 51 - air guide hole. Detailed implementation manners

[0053] Next, in combination with the embodiments of the present utility model, the technical solutions in the embodiments of the present utility model will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present utility model.

[0054] Referring to Figures 1-12 As shown, an embodiment of the present utility model provides a fuel tank isolation valve, including a valve body 1, a positive pressure valve unit 2, a negative pressure valve unit 3, and a solenoid valve unit 4, wherein:

[0055] A first cavity 11, a second cavity 12 and a partition 13 are provided inside the valve body 1. The second cavity 12 is arranged above the first cavity 11. A first channel 14 for connecting a carbon canister and a second channel 15 for connecting a fuel tank are respectively connected to the first cavity 11 and the second cavity 12. The partition 13 is arranged between the first cavity 11 and the second cavity 12, and a communication hole 131 is provided on the partition 13;

[0056] The positive pressure valve unit 2 includes a positive pressure valve seat 21, a positive pressure spring 22 and a sealing gasket 23. The positive pressure valve seat 21 is located in the first cavity 11; one end of the positive pressure spring 22 abuts against the bottom of the first cavity 11, and the other end of the positive pressure spring 22 abuts against the positive pressure valve seat 21; a first lip 231 and a second lip 232 are provided on the upper surface of the sealing gasket 23. The first lip 231 is used for sealingly fitting with the partition 13, and the second lip 232 is used for sealingly fitting with the negative pressure valve unit 3. The lower surface of the sealing gasket 23 is connected to the top surface of the positive pressure valve seat 21. The connection between the lower surface of the sealing gasket 23 and the top surface of the positive pressure valve seat 21 can be bonded with glue;

[0057] The negative pressure valve unit 3 includes a negative pressure valve seat 31 and a negative pressure spring 32. One end of the negative pressure spring 32 abuts against the solenoid valve unit 4, and the other end of the negative pressure spring 32 abuts against the negative pressure valve seat 31 to make the negative pressure valve seat 31 abut against the second lip 232; a gap 100 is provided between the negative pressure valve seat 31 and the peripheral wall of the communication hole 131;

[0058] The solenoid valve unit 4 is installed in the second cavity 12 and is connected to the negative pressure valve seat 31 to balance with the elastic force of the negative pressure spring 32 through magnetic force;

[0059] Wherein:

[0060] During positive pressure relief operation, the medium enters the second cavity 12 from the second channel 15. The medium pressure pushes the sealing gasket 23 and the positive pressure valve seat 21 to move downward, so that the first lip 231 disengages from the partition 13. The solenoid valve unit 4 stops working. The negative pressure valve seat 31 remains in contact with the second lip 232 under the action of the elastic force of the negative pressure spring 32. The medium enters the first cavity 11 from the gap 100 and is discharged to the carbon canister through the second channel 15;

[0061] When working with negative-pressure air replenishment, the solenoid valve unit 4 operates. The medium enters the first cavity 11 from the first channel 14. The medium pushes the negative-pressure valve seat 31 upward, causing the second lip 232 to disengage from the negative-pressure valve seat 31. Under the elastic force of the positive-pressure spring 22, the positive-pressure valve seat 21 keeps the first lip 231 in contact with the partition plate 13. After the medium enters the first cavity 11 from the gap 100, it is replenished into the fuel tank through the first channel 14.

[0062] For the fuel tank cut-off valve provided in this embodiment, through the above design, the distance between the positive-pressure valve seat 21 and the negative-pressure valve seat 31 can be reduced, which saves more space. At the same time, the negative-pressure valve unit 3 with a smaller pressure is arranged at one end of the solenoid valve unit 4, making the suction force required for the solenoid valve unit 4 smaller. Thus, the solenoid valve unit 4 can be made smaller synchronously, reducing the volume of the fuel tank cut-off valve.

[0063] In some embodiments, a second guide plate 211 is provided at the bottom of the positive-pressure valve seat 21, and a first guide plate 111 is provided at the bottom of the first cavity 11. The inner diameter of the first guide plate 111 is larger than that of the second guide plate 211, and the positive-pressure spring 22 is located between the second guide plate 211 and the first guide plate 111. Since the inner diameter of the first guide plate 111 is larger than that of the second guide plate 211 and the positive-pressure spring 22 is located between the second guide plate 211 and the first guide plate 111, the elastic force direction of the positive-pressure spring 22 is kept along the axis of the positive-pressure valve seat 21, making the first lip 231 of the gasket 23 fit more closely with the partition plate 13 and improving the sealing effect.

[0064] In some embodiments, a plurality of vent holes 2111 are formed in the outer wall of the second guide plate 211, and the first guide plate 111 includes at least two arc-shaped plates 1111 arranged at intervals. Since a plurality of vent holes 2111 are formed in the outer wall of the second guide plate 211 and the first guide plate 111 includes at least two arc-shaped plates 1111 arranged at intervals, the vent area between the second guide plate 211 and the first guide plate 111 is increased, avoiding affecting the flow of the gas medium, improving the efficiency of the medium flow, and thus improving the efficiency of pressure relief or air replenishment.

[0065] In some embodiments, the fuel tank isolation valve further includes a flow limiting valve 5. A flow limiting hole 112 communicating with the first channel 14 is provided at the bottom of the first cavity 11. The flow limiting valve 5 is installed in the flow limiting hole 112, and the flow limiting valve 5 is provided with a vent hole 51 communicating the first cavity 11 and the first channel 14. By installing the flow limiting valve 5 in the flow limiting hole 112 and providing the vent hole 51 communicating the first cavity 11 and the first channel 14, the size of the ventilation flow rate of the flow limiting valve 5 is realized by controlling the opening degree of the vent hole 51, so as to realize flow control, and further control the gas flow rate between the first cavity 11 and the first channel 14, and realize the control of the pressure relief and air replenishment speeds.

[0066] In some embodiments, a limiting protrusion 1121 is provided at the top of the flow limiting hole 112, and a guiding column 141 coaxial with the flow limiting hole 112 is provided in the first channel 14; the fuel tank isolation valve further includes a flow limiting spring 6. The flow limiting spring 6 is sleeved on the guiding column 141. One end of the flow limiting spring 6 abuts against the inner wall of the second channel 15, and the other end abuts against the bottom surface of the flow limiting valve 5, so that the top surface of the flow limiting valve 5 abuts against the limiting protrusion 1121. By abutting one end of the flow limiting spring 6 against the inner wall of the second channel 15 and the other end against the bottom surface of the flow limiting valve 5, the top surface of the flow limiting valve 5 abuts against the limiting protrusion 1121, thereby realizing the installation and fixation of the flow limiting valve 5 in the flow limiting hole 112.

[0067] In some embodiments, the solenoid valve unit 4 includes a housing 41, a coil 42 and a guide rod 43; the housing 41 is connected to the valve body 1, and a sliding hole 411 is provided inside the housing 41; the coil 42 is provided at the top of the housing 41 and is used to magnetically attract the guide rod 43 after being energized; the guide rod 43 is made of a magnetizable material, and the guide rod 43 is slidably installed in the sliding hole 411. By slidably installing the guide rod 43 in the sliding hole 411, the sliding hole 411 guides the sliding of the guide rod 43. After the coil 42 is energized, it magnetically attracts the guide rod 43, and the upward magnetic attraction force of the coil 42 is applied to the guide rod 43 and transmitted to the negative pressure valve seat 31, and the downward elastic force of the negative pressure spring 32 received by the negative pressure valve seat 31 is balanced.

[0068] In some embodiments, the solenoid valve unit 4 further includes a limit seat 44 located in the second cavity 12. The limit seat 44 includes a baffle 441 and a guide cylinder 442. The baffle 441 is connected to the guide rod 43, and the baffle 441 can abut against the end of the sliding hole 411. The guide cylinder 442 is connected to the end of the baffle 441 away from the coil 42. The negative pressure spring 32 is sleeved on the guide rod 43 and is located inside the guide cylinder 442. One end of the negative pressure spring 32 abuts against the baffle 441, and the other end of the negative pressure spring 32 abuts against the negative pressure valve seat 31. The baffle 441 abuts against the end of the sliding hole 411, forming a support point for the negative pressure spring 32, and the elastic force of the negative pressure spring 32 will not decrease as the guide rod 43 rises. When the negative pressure is eliminated, the negative pressure spring 32 can drive the negative pressure valve seat 31 to descend and reset, improving the stability and reliability of the device.

[0069] In some embodiments, the negative pressure valve seat 31 includes a base 311 and a connecting cylinder 312. The base 311 is used to abut against the second lip 232. The connecting cylinder 312 is arranged on the top of the base 311. A connecting cavity 3121 is arranged inside the connecting cylinder 312. An installation hole 3122 is arranged on the top surface of the connecting cylinder 312. The diameter of the installation hole 3122 is smaller than the diameter of the inner wall of the connecting cavity 3121. An axial groove section 431 is arranged at the end of the guide rod 43 away from the coil 42. The axial groove section 431 is arranged in the installation hole 3122, and the end of the guide rod 43 is located inside the connecting cavity 3121. By arranging the axial groove section 431 in the installation hole 3122 and the end of the guide rod 43 being located inside the connecting cavity 3121, the diameter of the end of the guide rod 43 is larger than the diameter of the installation hole 3122, and the end of the guide rod 43 is limited by the installation hole 3122, so that the guide rod 43 is connected to the negative pressure valve seat 31, and the guide rod 43 and the negative pressure valve seat 31 act together.

[0070] In some further embodiments, an installation groove 3123 is arranged on the outer wall of the connecting cylinder 312. The installation groove 3123 communicates with the connecting cavity 3121 and the installation hole 3122. The width of the installation groove 3123 is larger than the bottom diameter of the axial groove section 431. By arranging the installation groove 3123 on the outer wall of the connecting cylinder 312, the installation groove 3123 communicates with the connecting cavity 3121 and the installation hole 3122, and the width of the installation groove 3123 is larger than the bottom diameter of the axial groove section 431. When installing the guide rod 43, the axial groove section 431 area of the guide rod 43 is passed through the installation groove 3123, and the end of the guide rod 43 can be placed inside the connecting cavity 3121, improving the convenience of device installation, as well as the reliability and stability of the device.

[0071] In some embodiments, a plurality of first rib plates 16 are further disposed in the valve body 1. The plurality of first rib plates 16 are circumferentially arranged along the inner wall of the second cavity 12. The first rib plates 16 extend from the inner wall of the second cavity 12 in the diameter direction of the second cavity 12. One end of the first rib plate 16 away from the inner wall of the second cavity 12 is used to guide the negative pressure valve seat 31. While the first rib plate 16 can guide the negative pressure valve seat 31, it can strengthen the strength of the partition plate 13, avoid damage to the partition plate 13 due to excessive force, and improve the reliability and stability of the device.

[0072] In some embodiments, a plurality of second rib plates 17 are further disposed in the valve body 1. The plurality of second rib plates 17 are circumferentially arranged along the inner wall of the first cavity 11. The second rib plates 17 are respectively connected to the inner wall of the first cavity 11 and the partition plate 13. By connecting the second rib plates 17 to the inner wall of the first cavity 11 and the partition plate 13 respectively, the strength of the partition plate 13 is further strengthened, and the reliability and stability of the device can be further improved.

[0073] The working principle of this fuel tank cut-off valve is as follows:

[0074] During positive pressure relief operation, the medium enters the second cavity 12 from the second channel 15. The medium pressure pushes the sealing gasket 23 and the positive pressure valve seat 21 downward, so that the first lip 231 disengages from the partition plate 13. The solenoid valve unit 4 stops working. The negative pressure valve seat 31 remains in contact with the second lip 232 under the elastic force of the negative pressure spring 32. The medium enters the first cavity 11 from the gap 100 and is discharged to the carbon canister through the second channel 15;

[0075] During negative pressure air replenishment operation, the solenoid valve unit 4 works. The medium enters the first cavity 11 from the first channel 14. The medium pushes the negative pressure valve seat 31 upward, so that the second lip 232 disengages from the negative pressure valve seat 31. The positive pressure valve seat 21 makes the first lip 231 remain in contact with the partition plate 13 under the elastic force of the positive pressure spring 22. The medium enters the first cavity 11 from the gap 100 and is replenished into the fuel tank through the first channel 14.

[0076] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A fuel tank isolation valve, characterized in that: It includes a valve body, a positive pressure valve unit, a negative pressure valve unit and a solenoid valve unit, wherein: The valve body is provided with a first cavity, a second cavity and a partition, the second cavity is provided above the first cavity, the first cavity and the second cavity are respectively connected with a first channel for connecting to a carbon canister and a second channel for connecting to a fuel tank, the partition is provided between the first cavity and the second cavity, and a connecting hole is provided on the partition; The positive pressure valve unit comprises a positive pressure valve seat, a positive pressure spring and a sealing gasket, wherein the positive pressure valve seat is located in the first cavity; one end of the positive pressure spring abuts against the bottom of the first cavity, and the other end of the positive pressure spring abuts against the positive pressure valve seat; the upper surface of the sealing gasket is provided with a first lip and a second lip, the first lip is used for sealingly fitting with the partition, and the second lip is used for sealingly fitting with the negative pressure valve unit, and the lower surface of the sealing gasket is connected to the top surface of the positive pressure valve seat; The negative pressure valve unit is used to abut against the second lip, and a gap is provided between the negative pressure valve unit and the peripheral wall of the communicating hole; The solenoid valve unit is installed in the second cavity and connected to the negative pressure valve unit; Wherein: after the medium enters the second cavity from the second channel, it enters the first cavity from the gap and is discharged to the carbon canister through the first channel; or, after the medium enters the first cavity from the first channel, it enters the second cavity from the gap and is replenished to the fuel tank through the first channel.

2. The tank isolation valve according to claim 1, characterized in that: A second guide plate is disposed at the bottom of the positive pressure valve seat, a first guide plate is disposed at the bottom of the first cavity, an inner diameter of the first guide plate is larger than an inner diameter of the second guide plate, and the positive pressure spring is located between the second guide plate and the first guide plate.

3. The tank isolation valve according to claim 2, characterized in that: A plurality of air holes are formed on the outer wall of the second guide plate, and the first guide plate includes at least two arc-shaped plates arranged at intervals.

4. The fuel tank isolation valve according to claim 1, characterized in that: It also includes a flow limiting valve, the bottom of the first cavity is provided with a flow limiting hole connected with the first channel, the flow limiting valve is installed in the flow limiting hole, and the flow limiting valve is provided with an air guide hole connecting the first cavity and the first channel.

5. The fuel tank isolation valve according to claim 1, characterized in that: The negative pressure valve unit includes a negative pressure valve seat and a negative pressure spring, one end of the negative pressure spring abuts against the solenoid valve unit, and the other end of the negative pressure spring abuts against the negative pressure valve seat, so as to make the negative pressure valve seat abut against the second lip; the gap is provided between the negative pressure valve seat and the peripheral wall of the connecting hole.

6. The tank isolation valve according to claim 5, characterized in that: The solenoid valve unit includes a shell, a coil and a guide rod; the shell is connected to the valve body, and a sliding hole is provided inside the shell; the coil is arranged on the top of the shell, and is used to magnetically attract the guide rod after power is turned on; the guide rod is made of magnetic material, and the guide rod is slidably installed in the sliding hole.

7. The tank isolation valve according to claim 6, characterized in that: The solenoid valve unit also includes a limit seat located in the second cavity, and the limit seat includes a baffle and a guide cylinder; the baffle is connected to the guide rod, and the baffle can abut against the end of the sliding hole; the guide cylinder is connected to the end of the baffle away from the coil, and the negative pressure spring is sleeved on the guide rod and located in the guide cylinder.

8. The tank isolation valve according to claim 7, characterized in that: The negative pressure valve seat includes a base and a connecting tube, the base is used to abut against the second lip; the connecting tube is arranged on the top of the base, a connecting cavity is arranged inside the connecting tube, a mounting hole is arranged on the top surface of the connecting tube, the diameter of the mounting hole is smaller than the diameter of the inner wall of the connecting cavity, an axial groove section is arranged at one end of the guide rod away from the coil, the axial groove section is arranged in the mounting hole, and the end of the guide rod is located in the connecting cavity.

9. The tank isolation valve according to claim 8, characterized in that: The outer wall of the connecting cylinder is provided with a mounting groove, the mounting groove communicates with the connecting cavity and the mounting hole, and the width of the mounting groove is greater than the bottom diameter of the shaft groove section.

10. The fuel tank isolation valve according to any one of claims 5 to 9, characterized in that: A plurality of first ribs are also provided in the valve body, and the plurality of first ribs are arranged circumferentially along the inner wall of the second cavity. The first ribs extend from the inner wall of the second cavity along the diameter direction of the second cavity, and one end of the first rib away from the inner wall of the second cavity is used to guide the negative pressure valve seat.

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